Crimped Ammo & Accuracy

[Old Navy]

I will answer the question you asked. I have shot both taper crimped and factory crimped ammo in several AR-15's and a Savage bolt gun. The factory crimped stuff shot 1.5" to 2" but that was probably all the ammo was capable of with or without the crimp. I taper crimp AR ammo for 3 gun competition and coyote calling and I have not noticed any loss of accuracy on the taper crimped ammo VS the same ammo not crimped. Both my bolt gun and my AR will shoot the taper crimped, carefully loaded ammo into less than 1/2" at 100 yards. The reason I taper crimp for my AR is that I have found several bullets pushed back into the case so I taper crimp to prevent it. It also may help with feeding when the chamber on my competition gun gets dirty - just a theory.

Good post. Later! Frank

 

[bigedp51]

Google is your best friend

Crimped Ammo & Accuracy

Now start reading since you refuse to do your own side by testing. :

Don't read the first posting it would be redundant and "crimp" your style.

https://www.google.com/search?newwindow=1&site=&source=hp&q=Crimped+Ammo+%26+Accuracy+&oq=Crimped+Ammo+%26+Accuracy+&gs_l=hp.12...1834.1834.0.3263.1.1.0.0.0.0.89.89.1.1.0....0...1c.2.24.hp..1.0.0.m16mpng6jSo

 

[ar15topgun]

Black Hills crimps their ammo as does Atlanta Arms. Doesn't seem to hurt the scores of the military teams that shoot their ammo. I use a Lee taper crimp on my 200-300 short line loads and have no problem cleaning the HP target if I do my part.

 

[amlevin]

I guess it depends on what "crimping" is really done. If it's merely a slight crimp to make sure the case mouth is fully in contact with the bullet that's one thing. I do that with all my autoloader pistol rounds.

If the bullet has a cannelure then the cannelure itself is really a limiting factor in accuracy. I crimp my AR rounds because I tend to get crazy when shooting and hate a round getting the bullet stuffed back in the case and then failing to chamber correctly.

As for side/side comparisons on crimped vs non, I did some a couple years ago. I lightly crimped some 175 gr Nosler Custom Competition bullets in .308 cases using a lee factory crimp die. Not enough to really leave a mark on the bullet, just a fair "squeeze".

I did find that MY results showed more consistent SD, ES, MAD readings in strings shot over the Chronograph. It seemed to translate into some increase in accuracy but that could also have been me doing a better job on my end of the rifle.

 

[MikeMcCasland]

This article from Accurate Reloading is pretty interesting.

http://www.accuratereloading.com/crimping.html

 

[jcampbellsmith]

This article from Accurate Reloading is pretty interesting.

http://www.accuratereloading.com/crimping.html

No, I don't agree. I've not read of anyone developing a crimped load and a non-crimped load side by side with the same components for the same rifle and then getting a blind test done. I'm sure folk have done this, but I've not stumbled across their articles yet.
Regards
JCS

 

[nosualc]

Crimping is usually done to prevent bullet movement with heavy recoil or rough handling.

It is not typically a step used to improve accuracy. If it were, benchrest guys would be crimping. They don't.

-nosualc

ps - Phil3, google and the search function are your friends. You might want to try them.

 

[MikeMcCasland]

I guess I should have clarified, I'm not advocating crimping on the pretext that it will increase accuracy. I just thought the test performed by the accurate reloading guys was interesting, and certainly a result I wouldn't have expected. That said, for my reloading, I just crimp pistol/revolver cartridges and thats it.

Cheers!
Mike

 

[jlow]

Sometimes what is “conventional wisdom” is really not wisdom and that “wisdom” dies really hard, sometimes never…..

Take for instance the medical community (lots of smart guys – right? :), for over a hundred years the best gastroenterologist in the world believe that it was stomach acid that caused ulcers but in the 1990s, a new idea surface that it was a bacteria living in the stomach was the culprit – blasphemy says just about every gastroenterologist . The guy who came up with this idea eventually did the ultimate test which is to ingest this bacteria himself and show that it caused ulcer in his stomach… Trust me it is true history. Today, guess what, you will be hard press to find ONE gastroenterologist who thinks stomach ulcers are caused by acid.

Not that I advocate crimping but guess how many people on this thread that says it is bad have ever done a side-by-side test? My guess is “zero”.

 

[Phil3]

ps - Phil3, google and the search function are your friends. You might want to try them.

I had, but could not find any conclusive test that I felt I could depend on. Also, this group is very accuracy oriented and if anyone did a test here, it would likely be off a mechanical front rest and rear bag, lending more credibility to the results found.

Phil

 

[effendude]

I don't want to pick a fight, but this entire post was based on the potential accuracy (or lack of accuracy) of 50 rounds of ammo. Seriously, 2 pages of a serious website is taken up with what is ultimately a ridiculous question. If the OP has doubts about the accuracy potential of the ammo, he should sell it or give it away. Stop worrying whether the answers are serious, the answers should be a giant wake up call that the original post is not worth worrying about.